#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>

int my_strlen(char* str)
{
    char* strat = str;
    while (*str != '\0')
        str++;
    return str - strat;
}
int main()
{
    int len = my_strlen("abcdef");
    printf("%d\n", len);
    return 0;
}
